<?php
echo "6.428保留2位小数是：" . round( 6.428, 2 );
echo "-7.273保留2位小数是：" . round( -7.273, 2 );
echo "4保留2位小数是：" . round( 4, 2 );
echo "1.7150保留2位小数是：" . round( 1.7150, 2 );
echo "-0.0594保留2位小数是：" . round( -0.0594, 2 );